about the church of scientology. The book is written by the father of the church's leader. Who left the church four years ago. Now he's heart broken. George, good morning. The fact that Ron miscavige has written this book has made headlines all over the world. This morning, he explains why he said he did it. This morning, new claims about the secret world of scientology and the man at its center from an unusual source -- do you have good memories here. Ron miscavige, has left the church and he's speaking out for the first time exclusively to ABC news. Ron said he's written his book called "Ruseless" because of a scientology part called disconnection. I don't think you can do a worse thing to their family, split up a family. Reporter: This is what Ron said happen with his two daughters not long after he left the church seven years ago. The church says this is one of my blatant experiences of him not telling the full story. It's simply not true. Reporter: Through attorneys, Ron's daughters said they good reason to cut off ties with their father, they alleged he physically abused their mom as well as them. Strikingly them with his fists and belts. Ron's daughters have relaid that grew up in a house of chamber of horrors they said. He said his daughters' claims are greatly edge xated. The last straw for them was he moved into their older brother Ronnie. He denied it. Reporter: Ron's not only the ex-scientologist to complain about disconnection. This billboard went up condemning the practice. She says when the church and her ex-husband wanted their daughter to drop out of school to join the church at the age of 15, she objected to no avail. She wanted to dedicate her life to scientology. Reporter: Three years, her son sound the sea organize as well. As of right now, both of her children refuse to speak to her. It's not right what they're doing to families. Reporter: The church provided ABC news with video statements from both of her children saying they have voluntarily chosen not speak to her mother. She keeps doing to media and putting our personal information and our life for the world to see with false information. I think it's more important for her to have this vendetta against this church than have a relationship with me. Reporter: There's a policy of disconnection but insists it's a voluntary choice made by the members of the church. They do believe their spiritual progress would be impeded if they continue to communicate with someone who just attacks the church. Despite all the nastiness now erupting in public view David's father said he nurses some hope for reconciliation. The church said there's nothing to forgive, David has been a lovely and forgiving son. So reconciliation may be a long way off. Let's go outside to rob. All right, George, we're in

This transcript has been automatically generated and may not be 100% accurate.

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